This project involves the continued development and clinical evaluation of a microcomputer based instrumentation system for vestibular function testing. The overall goal of the project is the demonstrated utility of such of a stand-alone device in improving accuracy, reducing labor, and standardizing the procedures for such tests. A prototype instrument has been assembled during previous funding periods. One microprocessor instrument collects and analyzes nystagmus recorded via electrooculography and presents summary information to the operator. A second processor controls the generation of several vestibular stimuli including a moving chair and optokinetic and caloric stimulators. A clinical evaluation of the nystagmus analyzer will emphasize accuracy and reliability of the computer analysis of eye movements and degree of acceptance of the device by clinical users. As an aid in the evaluation process, work will begin on a digitized manually annotated, data base of a spectrum of vestibular and oculomotor response, both normal and abnormal. Computer analysis will be compared to the manual reading via a comparator program. The analysis algorithms will be adjusted for optimum performance using this tool. Alternate signal processing methods for vestibular-ocular responses will also be explored.